In known electrical power steering systems, the steering wheel torque exerted by the driver when the vehicle is in motion is measured by a dedicated torque sensor. The information thus obtained is subsequently processed by an on-board computer in order to determine the set point of the torque that must be applied to the steering column by the assistance motor, for example, in the case of turning.
These electrical power steering systems have the major disadvantage that the torque sensors have a complex and bulky structure and are difficult to use and calibrate.